Engine Oil Grade 1......SMSubaru has published Service Bulletin # 02-103-07 that identifies a factory design related problem with premature clogging of the oil mesh screen located inside the oiling system that supplies the turbo charger on all model turbo charged cars. A clogged screen will result in oil starvation and turbo charger failure. Subaru has since published Service Bulletin #02-110-10R indicating that 2010 MY and prior turbocharged engines continue to require oil and filter change intervals of 3,750 miles (6,000 km) or 3 3/4 months, while all 2011 MY turbocharged engines have returned to the original requirement of 7,500 miles (12,000 km) or 7 1/2 months, and they are required to use synthetic oil. Due to the issues outlined in this document, AMSOIL recommends following Subaru drain interval recommendations.